How do I go from being a hostess to a server?

I'm currently a hostess at Applebee's, I've been there for almost 3 months, and I'm making next to nothing. This is a side job for me on top of my full-time job, and the whole reason I wanted this job was to make money to pay off my college Ioans faster. Servers make much more money, so the whole point of my taking this job was to eventually become a server. I'm over 21, so I could be a server with no problems age-wise, but they made me a hostess because I didn't have any previous restaurant experience, and they told me if I did well, I could be a server within 3-4 months. I definitely do my best when I'm there, but I feel like I get yelled at a lot (though everyone does, especially when we're busy). If I want to be a server, should I bring it up to the manager, or wait for them to bring it up to me? And how should I go about bringing it up if I do?